问使用纯css3的键盘导航

EN

(function(){
 var slide = 0,  // Current slide 
     max   = 10, // Maximum Number of slides
 ele = document.getElementById("show");
     document.addEventListener('keydown',function(e){
          e.preventDefault();
          e.stopPropagation(); // To stop more event stuff and default behaviour
          key = e.keyCode; // To find out what key is this 
          if( key === 39 ){
              // Right arrow 
              // Aha we incremented the value!
              slide++;
              slide %= (max+1);
              // Increase the value of slide by 1 and keep em in limits
          }else if( key === 37){
              slide = (--slide >= 0)?slide: ( slide + max );
              // Will decrement the slide value by 1 and if they are less then 0 then   will cycle it to the last slide 
          }  

          ele.className.replace(/slide[0-9]/gi,'slide'+slide);                 
          // wasn't hard now was it ?     
     });
 })();